Bio 1

Question 1

Mention Sources of ammonia and its bood level

Answer 1

1- Deamination of amino acid 2 Trandamination of most amino acids. 2 steps de→Trans

3- Released during purines catabolism

4- intestinal bacteria.

5- glutamine → NH3 + glutamate

6- From monoamines by MAO.

its blood level 10:60 Mg/dL.

Question 2

Hepa Merz role in Treating Hyperammonia

Answer 2

LOLA adminstration increase Level of glutamate Level as They’re subtrates For glutamate transferase

ammonia as its utilized by making glutamine.

Question 3

Mechanism of Sodium benzoate in ammonia

Answer 3

Sodium bezoate and glycine make hippurate which excreted by kidney and help in ammonia Loss.

Question 4

How Lactulose decease nitogenous bad from gut

what also decrease it.

Answer 4

↓nitrogenous load through

1- Reduction of intestinal bacteria.

2- Acidification of The gut (Laculose lactic acid)

3-inhibit ammonia producing bacteria and increase non-ammonia producing bacteria

B/ Antibiotics

↓ Load by killing the bacteria.

Question 5

mention amino acids Yellds Acetoacetate Acetyl CoA

Answer 5

Ketogenic amino acids

Lucine Lysine

Question 6

Mention Mixed amino acids

Answer 6

Tyrosine
Tryptophan
Threonin
Iso lucine
phenylalanin
تف

Question 7

Mention causes of ammonia Toxicity

Answer 7

1- interfere ATP production of brain

use a ketoglutarate →glutamate not ATP

2-synthesis of glutamine from glutamate (GABA)

deletrious effects

3- increased ammonia cause increase permeability of K, CL which interfere electrical activity of The brain.

Question 8

How ammonia transported in The blood?

Answer 8

1- Free

2-Glutamine

3- Alanin

Alanin/Glucose cycle

Question 9

Rate limiting Enzyme of urea Cycle
- Its regulation.

Answer 9

• Carbomyl phosphate synthetasel

↑ activated by

Nacetyl glutamate whic its synthetase enzyme activated by Arginine

Question 10

area cycle and main points.

Answer 10

(1) carbo myl phosphate synthetase! 2 Atp
NH3 + CO2
N from ammonia

(2) make citrulline by
ornithine Transcarbamylase →
Cp+ ornithine.

B) Argininosuccinate by synthase
1 Atp
Citruline+ Aspartate (2nd N of urea)

(4) cleavage Argininosuccinate by
Arginosaccinase→
Arginine + Fumarate

(5) Arginin cleavage Arginase ornithine +urea.

Question 11

Q: Mention 2 major Transaminases and Their reactions

Answer 11

•ALT (pyruvic)

glutamate + pyruvic ←→a keto. + Alanin

•Ast (oxabacetate)

Glutamate + oxaloacetate←→α keto +aspartate

Question 12

Q: Mention amino acids can’t undergo transamination?

Q: What’s the Coenzyme for aminotransferases

Answer 12

A1:
1- Lysine
2-Threonine
3- proline, Hydroxy proline.

A2:
vit. B6 /plp

Question 13

Mention non-oxidative deamination enzymes.

Answer 13

1- Glutaminase

2- Asparginase

Question 14

Give example of axiditative deamination enzymes and their reactions.

Answer 14

(1) Glutamic Acid dehydrogenase

a keto. + NH3 ←→ glutamate
Reversible
NAD in oxidation
NADP in Reduction

inhibitors: ATP GTP NADPH activators: GDP ADP

(2) D-amino acid oxidase use FAD as coenzyme

Deaminate → Glycine

Question 15

Enumerate Fates of ammonia

Answer 15

1- urea cycle

2- Excreted by kidney as urine

3-synthesis of glutamine by kidney!

4. Smthesis of non-essential aminoa.

5- glutamate synthesis by GAD

Keto. + NH3 ←→Glutamate

Question 16

Define one carbon unit?

What are The Carriers?

Answer 16

Transfere a single C from a donor to an acceptor

carriers of carbon unit:

1- SAM carry (CH3)

2- Biotin Carry Co₂

3-THF carry all carbons at N5,N10

Question 17

What are types of one carbon unit?

Answer 17

CH3 Methyl

CH2 Methyelen

CH Methenyl

CHO Formyl group

CH=NH Formimino group

Question 18

Mention Sources of Methelyen. CH2

Answer 18

1- Beta carbon of Serine

Serine →→ glycine
by ser hydroxy methyl transferase

2 Glycine
glycine cleavage enzyme.

Question 19

Mention fate of Methylene.
CH2

Answer 19

1- Synthesis of thymidylate

2. oxidized to Methenyl-CH

3- Reduced to Methyl CH3

Question 20

Fate of Methenyl =CH

Answer 20

Hydrolysed to Formyl group THF

Question 21

Mentionall

Sources of MethenyL

Answer 21

1. Histidine

→Figlu→ 5- formimino THF ->

5.10 Methenyl THF

2- oxidation of Methynene.

CH2→ CH
NADP dehydrogenase.

Question 22

Mention Sources of Furmyl group 0=CH

Answer 22

1- Free Fumarate ATP activate it.

2- Tryptophan catabolism

3- Hydrolysis of methenyl.

Question 23

Q: Mention Fate of Formy L group 0=CH

Answer 23

synthesis of C2, C8 in purines

Question 24

Mention
Sources of Methyl
CH3

Answer 24

1. Reduction of Methylene_CH₂ by Reductase enzyme. (NAD linked)

Question 25

Mention Fate of CH3

Answer 25

• CH3 is taken by vitB12 Co.enz. →Form Methyl cobalamin transfer CH3 to Homocystine →Methionine

Question 26

What’s The cause of methyl trap?

Answer 26

vit B12 is defecient. THF is converted to Methy THF reservoir. which can’t be metabolized by any way.

THF is sinking →Folate defeciency

Question 27

tyrosine points

Answer 27

1- Mixed amino acids
2- make catecholamines (dopamine,. epinephrine)

Question 28

Glycine points

Answer 28

1- Sodium bezoate and glycine→ hippurate

2- deaminated by D-amino acid oxidase which use FAD as coenzyme

3- Sources of Methelyen CH2

Question 29

Arginine points

Answer 29

1- Activate the activator of Carbomyl phosphate synthetase 1

(N-acetyl glutamate synthetase )

2- its cleavage produce urea and ornithine

3- L-Arginin make Nitric oxide

Question 30

Histidine points

Answer 30

1- Source of CH THF
2- form histamine NT

Question 31

Typtophan points

Answer 31

1- tryptophan catabolism is a source of formyl group
2- make Seretonin

Question 32

Being a major degradative aminoacid pathway, lysine, proline and threonine are the only three amino acids that do not always undergo transamination and rather use respective dehydrogenase.